Palouse Region Of Eastern Washington Research Articles

Estimation of soil properties and wheat yields on complex eroded hills using geostatistics and thematic mapper images

Better assessment of large scale patterns in soil fertility, erosion, and crop productivity is needed to address environmental concerns in the steeply rolling dryland farming region of eastern Washington. Spatial variability of organic carbon, soil phosphorus, and wheat yields measured on several 655 m long transects in complex eroded hills of the Palouse region of eastern Washington was studied using classical statistics and geostatistics. In addition, Landsat Thematic Mapper images of bare soil at the study site were used to estimate organic matter content in blocks having an area of 28.5m × 28.5 m. Classical statistical analysis showed moderate coefficients of variation in soil properties (25–50%) and wheat yields (30%). Spherical semivariograms of soil properties and wheat yields showed strong spatial dependence, with a range of influence on the order of from 70 m to 145 m. The semivariogram for Landsat estimated organic matter was almost identical to that for organic matter measured in the surface transects. The cross-semivariogram between measured organic matter and wheat yields also exhibited strong spatial dependence, with a range of influence of about 120m. Organic matter, soil phosphorus, and wheat yield were interpolated at unsampled locations using block kriging and block cokriging techniques. Excellent agreement was obtained between kriged wheat yields and wheat yields cokriged from Thematic Mapper estimates of organic matter. Satisfactory agreement was obtained between kriged soil phosphorus and cokriged soil phosphorus based upon remotely sensed organic matter. Results of this study provided strong evidence for nonrandom spatial patterns in soil properties and crop yields. These spatial patterns are associated with changes in surface organic matter content across the landscape resulting from extensive erosion and exposure of subsoil. Geostatistical techniques provide a powerful tool for interpolating ground measurements of soil properties and crop yield over large areas in combination with estimates of organic matter obtained from Thematic Mapper images.

Plant development, and N and P use of winter barley

Winter barley (Hordeum vulgare L. cv. 'Kamiak') was grown at three landscape positions of a representative toposequence in the Palouse region of eastern Washington. This region is typified by rolling topography marked by severe erosion of steep slope positions that has altered soil productivity in the landscape. The objectives of this research were to identify soil factors which limit plant development and nutrient use efficiency in the eroded slope positions, and to suggest potential management practices for overcoming these limitations (...)

Plant development, and N and P use of winter barley

Winter barley (Hordeum vulgare L. cv. ‘Kamiak’) was grown at three landscape positions of a representative toposequence in the Palouse region of eastern Washington. This region is typified by rolling topography marked by severe erosion of steep slope positions that has altered soil productivity in the landscape. The objectives of this research were to identify soil factors which limit plant development and nutrient use efficiency in the eroded slope positions, and to suggest potential management practices for overcoming these limitations. Direct drilling into cereal stubble resulted in retardation of early plant development of winter barley. Lower N and P accumulation by early tillering under no-till conditions were related these effects on dry matter. These reductions were generally overcome by anthesis. Comparison of tillage systems demonstrated that direct drilling into crop residues increased yields by 16% over conventional tillage at an eroded ridgetop position of one of the two toposequences examined. Benefits derived in the no-till system under the high N rates occurred during grainfilling, as indicated by greater numbers of heads and higher kernel weights at final harvest. Tillage system had no effect on grain production at other landscape positions that featured higher overall yields under either tillage system. Short-term benefits of no-till systems may be most evident at slope positions where water use is most limited.

Multiple Origins of the Allotetraploid Tragopogon mirus (Compositae): rDNA Evidence

Tragopogon mirus is one of only a few polyploids whose time of origin is known with a high degree of certainty. Previous studies of morphological, karyotypic, and electrophoretic variation suggested multiple origins of allotetraploidy in T. mirus from the Palouse region of eastern Washington and adjacent Idaho. Restriction site analysis of the 17S-25S ribosomal RNA genes (rDNA) was used to test for multiple origins of T. mirus. The rDNA restriction profiles of six populations of T. mirus were compared with those of eight populations of T. dubius and six of T. porrifolius, the diploid progenitors. Populations of T. mirus combine the rDNAs of T. dubius and T. porrifolius, confirming the proposed origin of the tetraploid. Furthermore, the incorporation of restriction site polymorphisms of T. porrifolius into different populations of T. mirus demonstrates at least two independent origins of T. mirus. Although T. mirus often occurs with its diploid progenitors, these mixed populations do not necessarily reflect sites of origin of the tetraploid. In the three mixed populations examined, the diploids could not have produced the tetraploid plants found at the same site. Extensive dispersal of the tetraploid and fluctuating population sizes coupled with local extinctions and subsequent recolonization could explain the discordance between rDNA genotypes and their distributions. Thus, population dynamics in Tragopogon may obscure the sites of independent origin of T. mirus. Finally, although multiple origins of polyploid species have been reported frequently, few studies have demonstrated multiple polyploidization events on a geographic scale of a few kilometers. Tragopogon mirus Ownbey and T. miscellus Ownbey are well-documented products of allopolyploid speciation (Brehm and Ownbey 1965; Ownbey 1950; Ownbey and McCollum 1953, 1954; Roose and Gottlieb 1976; Soltis and Soltis 1989). Both allotetraploids arose within the current century in the Palouse region of eastern Washington and adjacent Idaho following the introduction and naturalization of their diploid progenitors, all of which are native to the Old World. The progenitors of T. mirus are T. dubius Scop. and T. porrifolius L., and those of T. miscellus are T. dubius and T. pratensis L. (Ownbey 1950). Whereas T. porrifolius and T. pratensis are restricted to waste places and lawns in a few towns within the Palouse, T. dubius and the allotetraploids have much broader distributions. Tragopogon dubius occurs in disturbed sites in towns and agricultural fields, along roadsides, and in disturbed areas of native vegetation in much of North America. The ranges of both tetraploid species have increased substantially in the Palouse since their discovery 40 years ago (Ownbey 1950; Novak et al. 1991). In addition, both T. mirus and T. miscellus have been reported from Arizona (Brown and Schaak 1972), and T. miscellus also occurs in Montana and Wy-

Diversity within Serogroups of Rhizobium leguminosarum biovar viceae in the Palouse Region of Eastern Washington as Indicated by Plasmid Profiles, Intrinsic Antibiotic Resistance, and Topography

Serology, plasmid profiles, and intrinsic antibiotic resistance (IAR) were determined for 192 isolates of Rhizobium leguminosarum biovar viceae from nodules of peas (Pisum sativum L.) grown on the south slope and bottomland topographic positions in eastern Washington State. A total of 3 serogroups and 18 plasmid profile groups were identified. Nearly all isolates within each plasmid profile group were specific for one of the three serogroups. Cluster analysis of IAR data showed that individual clusters were dominated by one serogroup and by one or two plasmid profile groups. Plasmid profile analysis and IAR analysis grouped 72% of the isolates similarly. Most plasmid profile groups and several IAR clusters favored either the south slope or the bottomland topographic position. These findings show that certain intraserogroup strains possess a greater competitiveness for nodulation and/or possess a greater ability to survive in adjacent soil environments.

Comparison of soil properties as influenced by organic and conventional farming systems

AbstractThis paper summarizes data from previous and current studies on two adjacent farms, one organically managed and the other conventionally managed, in the Palouse region of eastern Washington. The 320-hectare organic farm has been managed without the use of commercial fertilizers and only limited use of pesticides since the farm was first plowed in 1909. The 525-hectare conventional farm, first cultivated in 1908, began receiving recommended rates of commercial fertilizers and pesticides in 1948 and the early 1950's, respectively. The organically-farmed Naff silt loam soil had significantly higher organic matter, cation exchange capacity, total nitrogen, extractable potassium, water content, pH, polysaccharide content, enzyme levels, and microbial biomass than did the conventionally-farmed Naff soil. Also, the organically-farmed soil had significantly lower modulus of rupture, more granular structure, less hard and more friable consistence, and 16 centimeters more topsoil. This topsail difference between farms was attributed to significantly greater erosion on the conventionally-farmed soil between 1948 and 1985. The difference in erosion rates between farms was most probably due to their different crop rotation systems; Le., only the organic farm included a green manure crop in its rotation, and it had different tillage practices. These studies indicate that, in the long-term, the organic farming system was more effective than the conventional farming system in maintaining the tilth and productivity of the Naff soil and in reducing its loss to erosion.

Soil microbial biomass and selected soil enzyme activities: Effect of fertilization and cropping practices

Selected microbiological properties of soils receiving different fertilizer management regimes were studied from adjoining wheat farms in the highly productive Palouse region of eastern Washington. Since 1909, the only N input to the soil of Farm Management System 1 has been through leguminous green manure crops consisting most recently of Austrian winter peas ( Pisum sativum ssp. arvense L., Poir), plus native soil fertility for N and all other plant nutrients. The soil of Farm Management System 2 received regular applications of anhydrous ammonia, P and S at recommended rates for the last 30 yr. There were no differences in numbers of soil microorganisms as determined by plate counts; however, soil from management system 1 had significantly higher levels of urease, phosphatase and dehydrogenase at all three samplings and significantly higher soil microbial biomass at the first two samplings. The data indicate that management system 1 soil had a larger and more active soil microflora.

Equipment and Methods for No-Tillage Wheat Planting

ABSTRACT FOUR experiments were conducted to evaluate grain drill performance in no-tillage seeding of spring and winter wheat in the Palouse region of eastern Washington. The drill survey experiment showed similar stands and yields for six drills in winter wheat seeding, except that the highest two in yield were significantly better than the lowest yielder. The opener design experiment showed better winter wheat yields for the double disk opener in pea (light) residue, while the hoe openers gave significantly better yields in wheat and barley (heavy) residue. The use of colters did not effect yield but enhanced drill operation in heavy surface residue. The fertilizer placement experiment showed a significant 330 kg/ha (5 bu/acre) winter wheat yield increase for deep banded nitrogen fertilizer compared to broadcast for wheat and barley residue, but no difference for pea residue. For spring wheat planted into winter wheat and spring barley residues, subsurface banding of the fertilizer gave an advantage of approximately 723 kg/ha (11 bu/acre) compared with surface banding. A second fertilizer placement experiment done in the greenhouse indicated that the seed-fertilizer separation distance must be at least 50 mm (2 in.) to avoid seedling damage at the fertilizer rates and row spacing used in the experiment.

Is the soil frozen or not? An algorithm using weather records

Frozen soil water is important in hydrologic events because it reduces water infiltration. The presence of soil ice can be predicted reasonably well from detailed knowledge of the soil and microclimatic variables, but this type of information is generally unavailable. Consequently, the purpose of this study was to start with fundamental relations and see how well frozen soil conditions could be identified from daily weather station records of maximum‐minimum temperatures, solar radiation, and snowfall. Two relations were developed, one based on the soil‐atmosphere energy budget and the other on the heat flux across the soil surface layer. Conceptually, the two equations may be used together to give daily snowmelt as well as soil thawing and freezing rates, but in practice, the snowmelt prediction is probably not yet accurate enough for most practical applications. The simpler equation, describing the heat flux in the soil surface, does not require solar radiation input, yet it gave fair predictions of frozen soil on five diverse sites studied in the Palouse region of eastern Washington. Both approaches require only a single constant that accounts for individual site conditions such as slope, aspect, cover, and soil properties.

The Pacific Northwest Pea Industry

HE pea industry of the Pacific Northwest is one of the leading specialty crops. Dry peas are grown for seed and other purposes, and green peas, mostly of the sweet variety, are canned. In addition, fresh peas are sold in season for local consumption and increasing quantities are frozen for winter use. The raising of seed peas has been carried on for many years and the bulk of the pea seed of the nation comes from the Pacific Northwest. In contrast, the pea canning industry has been important for only a few years. Oddly enough, the Palouse region of eastern Washington and adjacent sections of Idaho raises peas only for seed, not for canning, yet for a generation has furnished a majority of the seed peas planted for canning. On the other hand, the Blue Mountain district now processes over one-fifth of the canned peas of the country yet raises little pea seed for sale.